You want the second arrangement. This is called a series connection: the positive lead from the lower battery holder connects to the negative of the upper battery holder. That leaves the positive lead of the upper connector free for BATT+ and the negative of the lower for BATT-.

As for the case, it's less than ideal. It's not a setup for certain disaster. It's more like choosing not to wear a seatbelt: you're choosing to do without a measure of protection.

I'm not sure which way I'd jump in that situation.

Replacement end panels and bezels are available, but you generally have to buy them in packs of 10 each. So, a new case ends up cheaper.

I believe the holes in the LNMP will accept up to 22 ga wire. I like stranded myself.

As for Teflon-coated wire, its main practical advantage comes in when the equipment will be exposed to the elements. Salt air, high humidity, etc. Navies love the stuff. But, it requires the better sort of wire strippers to cut, and it doesn't actually buy much in practicality other than the durability.

First, I forgot one advantage of Teflon coated wire: Teflon's melting point is way above normal soldering temperatures, so it can give a nicer finished look, if you're prone to making joints slowly.

Regular PVC insulation does melt at soldering temps, and when it does, it shrinks back away from the joint. So, not only may it expose some wire even though you started out with the insulation butted right up against the board, if you keep the iron on the joint it will then start to blacken. AFAIK, PVC-clad wire is all Radio Shack carries. (Ignoring the lacquer-clad magnet wire.)

But, there is another wire type that has this same benefit, and it's priced between regular PVC and Teflon: irradiated PVC. I use Alpha Wire from Mouser.

Quote:

bigger wire = more impedance, correct?

Exactly backwards. Both resistance and inductance go down as wire size increases.

Well, 300C is around, what, 570, so 600 is pretty close. I found it by experimentation. Thanks! I was really lost on the whole wire business, and relying on highest price wasn't really going to get me where I wanted to go.

would some of the aluminum tape used for duct work on the back of the plastic panels work as a degree of shielding instead of buying new panels? just wondering...

You'd have to tie it into the case somehow. Maybe the panel components would do that, but you'd want to check it with a continuity meter at least. I believe the specified BNC jack is isolated from its metal body, for example, so you couldn't count on it to tie the front panel to ground, or V-, or whatever you choose for the case shield connection.

You'd still have gaps along the edges, and where the stuff tears after you wrench the mounting nuts down, and...